This is the second time I have encountered this problem.
While building the Custom Rockets "Sport" kit, I needed to sand the root edges of the fins to get rid of the little balsa tab that holds each fin into the balsa blank. The fins are laser cut except for tiny little tabs that hold them into the sheet of 3/32" balsa.
So, what I do is I grab all of the fins and stack them together the same way.
Then I place piece of 220 grit sandpaper flat on my cutting mat. I try to hold it as flat and tight as I can.
Then, holding the group of fins together, I sand them on the 220 grit sandpaper. I use a straight back and forth motion, running parallel to the root edge.
When I examine each fin, the root edge of each fin has a slight curve in it! The top of the root edge curves away from the rest of the root edge just a tad. Same for the bottom of the root edge.
This keeps the fin from lying nice and flat on the body tube when I glue it on.
What am I doing wrong?
I tried used a circular motion, and even a side to side motion, and that seems to "flatten out" the root edge somewhat. I started to take quite a bit of wood off with all of this sanding.
The desk and the cutting mat seem pretty flat to me.
Any suggestions?
While building the Custom Rockets "Sport" kit, I needed to sand the root edges of the fins to get rid of the little balsa tab that holds each fin into the balsa blank. The fins are laser cut except for tiny little tabs that hold them into the sheet of 3/32" balsa.
So, what I do is I grab all of the fins and stack them together the same way.
Then I place piece of 220 grit sandpaper flat on my cutting mat. I try to hold it as flat and tight as I can.
Then, holding the group of fins together, I sand them on the 220 grit sandpaper. I use a straight back and forth motion, running parallel to the root edge.
When I examine each fin, the root edge of each fin has a slight curve in it! The top of the root edge curves away from the rest of the root edge just a tad. Same for the bottom of the root edge.
This keeps the fin from lying nice and flat on the body tube when I glue it on.
What am I doing wrong?
I tried used a circular motion, and even a side to side motion, and that seems to "flatten out" the root edge somewhat. I started to take quite a bit of wood off with all of this sanding.
The desk and the cutting mat seem pretty flat to me.
Any suggestions?